Conventional milling machines have a cutter mounted on a cutter drive shaft which is axially adjustable. As the tool rotates it cuts a groove or swath in the workpiece. If the workpiece is small, it may be mounted on a bed movable to a limited extent in an x and a y direction. Motion in the z direction is provided by axial advancement of the cutter drive shaft. This set-up is suitable for pieces of limited, relatively small size, weight, and regular configuration.
Where the piece is large, so that it will not fit on the bed in a manner that it can be controllably moved in the x or y direction, the cutting head must be stopped, the cutter repositioned, and a second groove cut. Subsequent adjacent grooves must be cut by the stop/adjust, stop/adjust, stop/adjust method, which is laborious and slow.
Further, a major cost of the milling machine is in the bed, including slides, hold downs, and the screw threaded x/y position assembly. The bed must support the mass of the work and must be smoothly and accurately positionable to insure precision of cut. Similarly, when lathes are set up to rotate the tool against a fixed piece, the work holder limits the size of the work that can be shaped. The same stop/adjust process must be employed to remove radially contiguous areas of metal.
While the prior art shows adjustable cutters which permit adjustment during the cutting process, they require a substantial number of moving parts and are of a more complex manufacture. For example, in the Milewski Pat. No. 3,530,745, a cam assembly with various springs, fasteners, cartridges, cutters and other elements is required to achieve the desired movement of the cutting edge.
There is thus a need for a simple fly cutting tool that is adjustable in the x, y and z directions during lathe operation. Such a simple, adjustable fly cutter tool that was continuously or intermittently positionable in the x, y and z directions during rotation of the tool would render milling machines and lathes more versatile, capable of handling larger stationary blanks, capable of working on irregular blanks, cheaper to manufacture in not requiring complex work-holding beds with their precision x and y motion assemblies. Further, such a fly cutter tool that is continuously adjustable during operation would save substantial labor time and cost in milling and lathe operations on stationary work pieces. These needs are satisfied by the instant invention.